A technology exists for encrypting data with an encryption key in an HDD (Hard Disk Drive) inside a storage device of a storage system to improve security (Patent Literature 1). A technology also exists for encrypting data, and upon storing the data over a long period of time, exchanging stored encrypted data on the basis of a new set of encryption standards (Patent Literature 2). Further, a technology exists for generating and managing an encryption key using a key management server different from a storage device in order to improve security in consideration of theft of an HDD or the like (Patent Literature 3).
In the case where the encryption key is generated and managed using the key management server different from the storage device as disclosed in Patent Literature 3, the storage device per se does not generate the key. Therefore, in the case where maintenance or exchange of a controller is performed when a fault is caused in the controller in the storage device, a newly exchanged controller or a spare controller does not have an encryption key, and therefore necessity of deriving a key from the key management server (KMS server) is caused. Thus, a method can be considered for acquiring key information from an exchanged controller by LAN communication to the key management server. However, the key information is acquired after the exchanged controller comes into a ready state, and therefore a problem of taking time for starting up of the exchanged controller is produced.